running lean help needed

[cliosport-carl]

so i went for a remap the otherday at tdf and the car when it was on the rollers started spluttering and misfireing. Was advised to change my fuelpump as this could be at fault because it was running lean as i had a spare i wacked this on to no joy also had some injectors from a previous fault this also didnt cure this and im at abit of a loss now the car is a 172 with a decat and supersprint exhaust with matched inlets and a ph1 airbox magnecore leads and 3 months new plugs. the car itself drives fine unless you like leave it in higher gear then try to accelerate it misfires and splutters. any help would be tried and tested thanks.

 

[BIGASH]

Doesn't sound ideal, did you take it for a remap to try and get rid of these issues or was it fine before?

 

[DannyR]

Sounds more like a coil pack.

I've NEVER seen a fuel pump fail on a 172.

Then again it could be an "excuse"

 

[cliosport-carl]

it didnt get remapped because of this i was hoping it would help the fueling but and before it would struggle to pick up speed if left in a higher gear.. the first time i changed the injectors i noticed one of the o rings on the connection for the rail in there was a bit shitty also the pump i had spare has been kept in a spare fueltank for the past year so probbaly not the best but it was worth a try

 

[cliosport-carl]

no matt is a good friend i was there when it happend and the fuel reedind was wrong ill try a coilpack the mrs has a 182 i can borrow parts off so as i said will try more parts first but when my leads went the misfire happend under any load of the engine not just when the demand for fuel was there like being in a higher gear and trying to pull

 

[Chip-mk1]

Crazy to try and remap a car while it has running issues!

If it was anything other than an off the shelf remap then its going to be a mile out if its been developed round a problem.

 

[cliosport-carl]

it hasnt been remapped i took it up for a map as i didnt think it had a problem i just thought it was poor fuel delivary due to the mods when it was on the roller then the fault became apparent then the car was taken off to fix

 

[cliosport-carl]

Tried some bits today of the Mrs working car fuel pump coilpack injectors even throttle pedal still no joy still hesitates when in a higher gear trying to accelerate and missfires and coughs and I am at a total loss now

 

[DannyR]

Why didnt Matt at TDF plug it in on his diagnostics

 

[darrenclio172]

I understand looking at the coil pack if there is hesitation at higher revs/load but you will be getting a richer mixture with a faulty coil due to unburnt fuel.

I would start by looking at the MAP or TPS sensors.

Has the fuel pressure been monitored when the fault occurs ?

 

[cliosport-carl]

I only took it to matt for the remap so didn't get anything else done and no nothing was monitored bar the readings on the rollers and the mixture

 

[DannyR]

He would of been plugged into the OBD port anyway, wouldn't of taken 10 minutes to plug it in and diagnose.

 

[cliosport-carl]

I didn't get him to as we thought it was the fuel pump

 

[Chip-mk1]

Check the fuel pressure. Only way to know if its the pump.

 

[Dan519]

Sounds like a shot lambda to me.

 

[Chip-mk1]

Sounds like a shot lambda to me.

Far more likely than the pump if its happening at lower revs and not higher rpm (pump working hardest at higher rpm)